Rhino 5 Validation Fails on Windows 11
Background
Rhino 5 for Windows was developed and tested on Windows 8 and Windows 10, and those are the only supported operating systems. See the Rhino 5 system requirements.
Rhino 5 was not developed for Windows 11, so it is not supported there. Some customers have been able to run Rhino 5 on Windows 11 versions up to 24H2, but not all.
Windows 11 25H2
In the fall of 2025, Windows 11 25H2 began shipping on new computers. Since then, Rhino 5 customers have reported more validation failures, specifically that Rhino 5 cannot reach our validation server.
Rhino 5 connects to the validation server using TLS 1.0 and 1.1. Internet standards and regulatory bodies have deprecated these versions because of security issues, and Microsoft has said that support for them may be removed from Windows completely in the future.
The Issue
On Windows 11 25H2, Rhino 5 cannot reach our validation server, so it cannot get a validation code.
If Rhino 5 was already installed and validated on Windows 11 24H2 or earlier, it keeps running after an upgrade to 25H2, because it already has its validation code and license files.
On computers running Windows 11 25H2 or later, Rhino 5 cannot be validated.
Workaround: Offline Validation
If Rhino 5 fails to validate on Windows 11, you can try validating offline. We no longer recommend or support this for Rhino 5 on Windows 11.
With offline validation:
- You get only one offline validation per computer.
- Before you can install Rhino 5 on another computer, you must contact McNeel Sales to remove the offline validation.
Microsoft Recommendations
Microsoft documents registry workarounds in TLS 1.0 and TLS 1.1 deprecation in Windows. We have not been able to get these to work on the customer computers we have tried.
If these suggestions work for you, please let us know at tech@mcneel.com.
